Tropical Cyclone, Threat to Southern Japan

The atmospheric setting of the tropical western Pacific Ocean is becomingincreasingly favorable for spinning up a tropical storm that could threatensouthern Japan early next week.

AccuWeather.com satellite imagery ofthe cyclone threat to Japan on Thursday, Aug. 5, 2010.As of Thursday, the makings for an organized tropical system took the formof widespread showers and thunderstorms over the southern Philippines Sea farto the east of the Philippines.Movement of this broad swath of disturbed weather will be towards the northand northwest and, by later Saturday, a tropical depression, even a namedtropical storm, could be under way.

Although the piled-up moisture necessary to form the core of a would-betropical cyclone has already gathered in the area in question, the upperatmosphere has thus far stayed unfavorable for tropical cyclone development. Anexpected shift to a more favorable, "less shearing" in the words of tropicalstorm forecasters, environment is the basis for the tropical cyclone threat forsouthwestern Japan.

In the event that the upper wind flow becomes favorable to the fullestextent, a typhoon, a tropical cyclone of hurricane strength, would wrap up overwaters south of southwestern Japan by next Tuesday.

Less-than-optimal atmospheric conditions could still bring a rain-ladentropical storm or depression landfalling to southwestern Japan early next week.

At this time, the most likely scenario would be the latter, in whichtorrential, flooding rain would pose the greatest weather threat to life andproperty.